Effect of LAT2 on glutamine-dependent mTOR activation to promote glycolysis and chemoresistance in pancreatic cancer.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e15759-e15759
Author(s):  
Jiangdong Qiu ◽  
Mengyu Feng ◽  
Zhe Cao ◽  
Gang Yang ◽  
Yueze Liu ◽  
...  

e15759 Background: Reprogrammed energy metabolism has become the characteristic of cancer recently. Transporters act as amino acid sensors involved in mTOR recruitment and activation, which is crucial for the growth of both normal and tumor cells. L-type amino acid transporter 2 (LAT2), a Na+ -independent neutral amino acid transporter, is encoded by the SLC7A8 gene and responsible for transporting neutral amino acids, including a mTOR activator, glutamine. LAT2 was reported to be overexpressed in gemcitabine-resistant pancreatic cancer cells. However, the role of LAT2 in chemoresistance in pancreatic cancer remains unclear. Methods: The effects of LAT2 on biological behaviors of pancreatic cancer cells were analyzed. LAT2 and LDHB levels in tissues were detected, and the clinical value was evaluated. Results: We demonstrated that LAT2 played an oncogenic role and decreased the gemcitabine sensitivity of pancreatic cancer cells in vitro and in vivo. Survival analysis indicated that high expression of both LAT2 and LDHB was related to a poor prognosis in patients with pancreatic cancer. Furthermore, we found that LAT2 could promote proliferation, inhibit apoptosis, activate glycolysis and alter glutamine metabolism to activate mTOR in vitro and in vivo. Next, the combination of gemcitabine with an mTOR inhibitor (RAD001) could reverse the decrease in chemosensitivity caused by LAT2 overexpression in pancreatic cancer cells. Mechanistically, LAT2 promoted glycolysis and decreased gemcitabine sensitivity via regulating two glutamine-dependent positive feedback loops (the LAT2/p-mTORSer2448 loop and the glutamine/p-mTORSer2448/glutamine synthetase loop) in pancreatic cancer. Conclusions: Our data indicates that LAT2 functions as an oncogenic protein and could regulate glutamine-dependent mTOR activation to promote glycolysis and decrease gemcitabine sensitivity in pancreatic cancer. The LAT2-mTOR-LDHB pathway might be a promising therapeutic target in pancreatic cancer.

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2608 ◽  
Author(s):  
Sungwoo Hong ◽  
Zhenghuan Fang ◽  
Hoi-Yun Jung ◽  
Jin-Ha Yoon ◽  
Soon-Sun Hong ◽  
...  

To investigate the amino acid transporter-based prodrug anticancer strategy further, several amino acid-conjugated amide gemcitabine prodrugs were synthesized to target amino acid transporters in pancreatic cancer cells. The structures of the synthesized amino acid-conjugated prodrugs were confirmed by 1H-NMR and LC-MS. The pancreatic cancer cells, AsPC1, BxPC-3, PANC-1 and MIAPaCa-2, appeared to overexpress the amino acid transporter LAT-1 by conventional RT-PCR. Among the six amino acid derivatives of gemcitabine, threonine derivative of gemcitabine (Gem-Thr) was more effective than free gemcitabine in the pancreatic cancer cells, BxPC-3 and MIAPaCa-2, respectively, in terms of anti-cancer effects. Furthermore, Gem-Thr was metabolically stable in PBS (pH 7.4), rat plasma and liver microsomal fractions. When Gem-Thr was administered to rats at 4 mg/kg i.v., Gem-Thr was found to be successfully converted to gemcitabine via amide bond cleavage. Moreover, the Gem-Thr showed the increased systemic exposure of formed gemcitabine by 1.83-fold, compared to free gemcitabine treatment, due to the significantly decreased total clearance (0.60 vs. 4.23 mL/min/kg), indicating that the amide prodrug approach improves the metabolic stability of gemcitabine in vivo. Taken together, the amino acid transporter-targeting gemcitabine prodrug, Gem-Thr, was found to be effective on pancreatic cancer cells and to offer an efficient potential means of treating pancreatic cancer with significantly better pharmacokinetic characteristics than gemcitabine.


2010 ◽  
Vol 999 (999) ◽  
pp. 1-11
Author(s):  
P. Ulivi ◽  
C. Arienti ◽  
W. Zoli ◽  
M. Scarsella ◽  
S. Carloni ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2017
Author(s):  
Lital Sharvit ◽  
Rinat Bar-Shalom ◽  
Naiel Azzam ◽  
Yaniv Yechiel ◽  
Solomon Wasser ◽  
...  

Pancreatic cancer is a highly lethal disease with limited options for effective therapy and the lowest survival rate of all cancer forms. Therefore, a new, effective strategy for cancer treatment is in need. Previously, we found that a culture liquid extract of Cyathus striatus (CS) has a potent antitumor activity. In the present study, we aimed to investigate the effects of Cyathus striatus extract (CSE) on the growth of pancreatic cancer cells, both in vitro and in vivo. The proliferation assay (XTT), cell cycle analysis, Annexin/PI staining and TUNEL assay confirmed the inhibition of cell growth and induction of apoptosis by CSE. A Western blot analysis demonstrated the involvement of both the extrinsic and intrinsic apoptosis pathways. In addition, a RNAseq analysis revealed the involvement of the MAPK and P53 signaling pathways and pointed toward endoplasmic reticulum stress induced apoptosis. The anticancer activity of the CSE was also demonstrated in mice harboring pancreatic cancer cell line-derived tumor xenografts when CSE was given for 5 weeks by weekly IV injections. Our findings suggest that CSE could potentially be useful as a new strategy for treating pancreatic cancer.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Feng Guo ◽  
Yingke Zhou ◽  
Hui Guo ◽  
Dianyun Ren ◽  
Xin Jin ◽  
...  

AbstractNR5A2 is a transcription factor regulating the expression of various oncogenes. However, the role of NR5A2 and the specific regulatory mechanism of NR5A2 in pancreatic ductal adenocarcinoma (PDAC) are not thoroughly studied. In our study, Western blotting, real-time PCR, and immunohistochemistry were conducted to assess the expression levels of different molecules. Wound-healing, MTS, colony formation, and transwell assays were employed to evaluate the malignant potential of pancreatic cancer cells. We demonstrated that NR5A2 acted as a negative prognostic biomarker in PDAC. NR5A2 silencing inhibited the proliferation and migration abilities of pancreatic cancer cells in vitro and in vivo. While NR5A2 overexpression markedly promoted both events in vitro. We further identified that NR5A2 was transcriptionally upregulated by BRD4 in pancreatic cancer cells and this was confirmed by Chromatin immunoprecipitation (ChIP) and ChIP-qPCR. Besides, transcriptome RNA sequencing (RNA-Seq) was performed to explore the cancer-promoting effects of NR5A2, we found that GDF15 is a component of multiple down-regulated tumor-promoting gene sets after NR5A2 was silenced. Next, we showed that NR5A2 enhanced the malignancy of pancreatic cancer cells by inducing the transcription of GDF15. Collectively, our findings suggest that NR5A2 expression is induced by BRD4. In turn, NR5A2 activates the transcription of GDF15, promoting pancreatic cancer progression. Therefore, NR5A2 and GDF15 could be promising therapeutic targets in pancreatic cancer.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kim Rouven Liedtke ◽  
Sander Bekeschus ◽  
André Kaeding ◽  
Christine Hackbarth ◽  
Jens-Peter Kuehn ◽  
...  

2000 ◽  
Vol 118 (4) ◽  
pp. A540
Author(s):  
Thomas Seufferlein ◽  
Michael J. Seckl ◽  
Michael Beil ◽  
Hardi Luhrs ◽  
Roland M. Schmid ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Jassim M. Al-Hassan ◽  
Daoyan Wei ◽  
Sharmistha Chakraborty ◽  
Tara Conway ◽  
Patrea Rhea ◽  
...  

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer related death in western countries. The successful treatment of PDAC remains limited. We investigated the effect of Fraction B, which is a fraction purified from catfish (Arius bilineatus, Val.) skin secretions containing proteins and lipids, on PDAC biology both in-vivo and in-vitro. We report here that Fraction B potently suppressed the proliferation of both human and mouse pancreatic cancer cells in vitro and significantly reduced the growth of their relevant xenograft (Panc02) and orthotopic tumors (human Panc-1 cells) (p < 0.05). The Reverse Phase Protein Array (RPPA) data obtained from the tumor tissues derived from orthotopic tumor bearing mice treated with Fraction B showed that Fraction B altered the cancer stem cells related pathways and regulated glucose and glutamine metabolism. The down-regulation of the cancer stem cell marker CD44 expression was further confirmed in Panc-1 cells. CBC and blood chemistry analyses showed no systemic toxicity in Fraction B treated Panc-1 tumor bearing mice compared to that of control group. Our data support that Fraction B is a potential candidate for PDAC treatment.


2021 ◽  
Vol 8 ◽  
Author(s):  
Fei Xu ◽  
Heshui Wu ◽  
Jiongxin Xiong ◽  
Tao Peng

Gemcitabine (GEM) resistance remains a challenging clinical issue to overcome in chemotherapy against pancreatic cancer. We previously demonstrated that miR-210 derived from pancreatic cancer stem cells enhanced the GEM-resistant properties of pancreatic cancer cells, thus identifying miR-210 as an oncogenic miRNA. Herein, we report the existence of an upstream effector that acts as a competing endogenous RNA (ceRNA) to miR-210. Bioinformatic screening was performed to identify lncRNAs with a binding relationship to miR-210. Overexpression and interference vectors were constructed to demonstrate the effect of ceRNA activity in pancreatic cell behavior, both in vitro and in vivo. DLEU2L (deleted in lymphocytic leukemia 2-like), which is expressed at low levels in pancreatic cancer tissues, was shown to exhibit a binding relationship with miR-210-3p. Overexpression of DLEU2L and silencing of miR-210-3p suppressed the proliferation, migration, and invasion of pancreatic cancer cells while promoting apoptosis. These effects occurred via the inhibition of the Warburg effect (aerobic glycolysis) and AKT/mTOR signaling. In addition, we showed that BRCA2 is a target gene of miR-210-3p, and the downregulation of miR-210-3p by DLEU2L effectively induced an upregulation of BRCA2 via the ceRNA mechanism. In vivo, DLEU2L overexpression and miR-210-3p interference suppressed pancreatic tumor progression, consistent with the results of in vitro studies. The findings of our study establish DLEU2L as a ceRNA to miR-210-3p and reveal the critical role of the DLEU2L/miR-210-3p crosstalk in targeting GEM resistance.


Pancreas ◽  
2008 ◽  
Vol 37 (4) ◽  
pp. 480
Author(s):  
A. Li ◽  
S. Hasan ◽  
E. Angst ◽  
J. Park ◽  
H. A. Reber ◽  
...  

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